1. Field of The Invention
The invention particularly concerns a novel, highly efficient and practical drive mechanism for the front end processing cylinders, roll pairs and the like of the card.
2. Background Information
In a typical card, a web or lap is processed in a carding operation to produce a sliver for subsequent processing into textile yarn. The lap is generally in the form of a web of textile material wound on a lap pin which is supported on the card for unwinding and feeding to a main cylinder where it is carded. The textile material is removed from the carding cylinder by a doffer cylinder which rotates closely adjacent the carding cylinder on the end opposite the lap roll. The doffer cylinder is normally driven by a take-off from the main drive of the carding cylinder through a production gear. The production gear is engaged and disengaged with a ring gear mounted on the shaft of the doffer cylinder by means of raising and lowering a drop lever on which the production gear is carried. Other drive arrangements are also utilized. The lap roll is normally driven by a take-off from the doffer cylinder. The web of textile material removed by the doffer cylinder is subsequently drawn therefrom and progressively passed through crush-rolls and calendar-rolls and condensed into a sliver which is deposited into a coiler can for transportation and further processing. It is important that a uniform weight and quality of sliver be deposited in the coiling can.
3. Discussion Of Prior Art
The front end of the card typically comprises the doffer cylinder, crush-rolls and calendar-rolls which are usually driven separately from the carding cylinder and which are drivingly interconnected by a complex series of gears, sprockets and chains as shown in U.S. Pat. Nos. 3,965,401 and 4,027,358, the disclosures of which relating to the general structure and operation of cards are incorporated herein by reference.
Such prior, near solid hook-up driving mechanisms between the doffer, crush-rolls and calendar-rolls requires, of course, nearly constant lubrication and wear maintenance, and is quite costly to repair or replace. Also, the speeds with which the crush-rolls and calendar-rolls may be run through such a near solid drive device are limited, due in part to the non-uniformity of fiber web thickness and weight issuing from the front end as a result of the almost imperceptible rotational speed irregularities inherent in such drive devices. For example, the doffer of a typical card having such near solid drive construction should not be run faster than about 22 revolutions per minute to process 30-33 pounds of fiber per hour into a 55-60 grain silver, otherwise, marked irregularities in texture, composition or weight of the silver can occur.
Objects therefore, of the present invention are: to provide a drive mechanism for the fiber processing system of the front end of a textile card which minimizes maintenance and cost thereof and which allows substantially higher operating speeds and silver output of the card without sacrificing product quality; to reduce the number and structural complexity of the drive mechanism components; and to provide such a mechanism which can be installed on practically any conventional card with a minimum of alteration thereof.